Franck Courchamp, Luděk Berec, and Joanna Gascoigne
- Published in print:
- 2008
- Published Online:
- May 2008
- ISBN:
- 9780198570301
- eISBN:
- 9780191717642
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198570301.003.0003
- Subject:
- Biology, Biodiversity / Conservation Biology
Much of what is known about Allee effects comes from mathematical models. This chapter deals with models of demographic Allee effects. It shows what types of model are available, what their ...
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Much of what is known about Allee effects comes from mathematical models. This chapter deals with models of demographic Allee effects. It shows what types of model are available, what their underlying assumptions are, how they can be used, and how they have contributed to our understanding of the dynamical consequences of Allee effects, both in single-species populations and multiple-species communities. The chapter does not provide detailed information on how to develop and analyse any single model, nor discusses the structure and predictions of every model that has ever been used to study Allee effects. Rather, it is conceived as a sort of summary of a large amount of literature that has been published on models which address Allee effects: providing a comprehensive (if a little dense) overview of the topic.Less
Much of what is known about Allee effects comes from mathematical models. This chapter deals with models of demographic Allee effects. It shows what types of model are available, what their underlying assumptions are, how they can be used, and how they have contributed to our understanding of the dynamical consequences of Allee effects, both in single-species populations and multiple-species communities. The chapter does not provide detailed information on how to develop and analyse any single model, nor discusses the structure and predictions of every model that has ever been used to study Allee effects. Rather, it is conceived as a sort of summary of a large amount of literature that has been published on models which address Allee effects: providing a comprehensive (if a little dense) overview of the topic.
Garcia Alcubilla and Ruiz del Pozo
- Published in print:
- 2012
- Published Online:
- May 2012
- ISBN:
- 9780199608867
- eISBN:
- 9780191739125
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199608867.003.0003
- Subject:
- Economics and Finance, Financial Economics, Macro- and Monetary Economics
Due to the financial crisis, a new European System of Financial Supervisors including a new authority, ESMA, in charge of the oversight of rating agencies, was established. The chapter presents an ...
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Due to the financial crisis, a new European System of Financial Supervisors including a new authority, ESMA, in charge of the oversight of rating agencies, was established. The chapter presents an overview of this new financial architecture and provides an in-depth analysis of the European Regulation on rating agencies. It explains the regulatory use of ratings in the EU, analysing the ECAI recognition process of the Capital Requirements Directive, which implements the Basel framework. It also examines the registration process and the supervision and enforcement framework, and ESMA’s sanctioning powers. Finally, the chapter analyses in detail the requirements to enhance agencies’ governance, to manage conflicts of interest, to improve the processes to develop and review methodologies and models, and to increase disclosures on individual ratings and on transparency of agencies’ activities. The Regulation is examined in light of all relevant guidance from ESMA, IOSCO, and other supervisors, related EU legislation, and SEC’s rules.Less
Due to the financial crisis, a new European System of Financial Supervisors including a new authority, ESMA, in charge of the oversight of rating agencies, was established. The chapter presents an overview of this new financial architecture and provides an in-depth analysis of the European Regulation on rating agencies. It explains the regulatory use of ratings in the EU, analysing the ECAI recognition process of the Capital Requirements Directive, which implements the Basel framework. It also examines the registration process and the supervision and enforcement framework, and ESMA’s sanctioning powers. Finally, the chapter analyses in detail the requirements to enhance agencies’ governance, to manage conflicts of interest, to improve the processes to develop and review methodologies and models, and to increase disclosures on individual ratings and on transparency of agencies’ activities. The Regulation is examined in light of all relevant guidance from ESMA, IOSCO, and other supervisors, related EU legislation, and SEC’s rules.
Andy Hector
- Published in print:
- 2015
- Published Online:
- March 2015
- ISBN:
- 9780198729051
- eISBN:
- 9780191795855
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198729051.003.0011
- Subject:
- Biology, Biomathematics / Statistics and Data Analysis / Complexity Studies, Ecology
Generalized linear mixed-effects models (GLMMs) are introduced as a combination of the mixed-effects models and GLMs met in earlier chapters. The additional challenges of the analysis are explored ...
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Generalized linear mixed-effects models (GLMMs) are introduced as a combination of the mixed-effects models and GLMs met in earlier chapters. The additional challenges of the analysis are explored and the differences in the R software functions and its output are explained. Model comparison and selection can be done using information criteria or likelihood ratio tests. In addition to the AIC and BIC the DIC was devised for use with multilevel models. The options for assessing how well the model assumptions are met are reduced relative to linear models and GLMs but the most accessible current options are demonstrated.Less
Generalized linear mixed-effects models (GLMMs) are introduced as a combination of the mixed-effects models and GLMs met in earlier chapters. The additional challenges of the analysis are explored and the differences in the R software functions and its output are explained. Model comparison and selection can be done using information criteria or likelihood ratio tests. In addition to the AIC and BIC the DIC was devised for use with multilevel models. The options for assessing how well the model assumptions are met are reduced relative to linear models and GLMs but the most accessible current options are demonstrated.
Michaël Tatham
- Published in print:
- 2016
- Published Online:
- August 2016
- ISBN:
- 9780198758624
- eISBN:
- 9780191818547
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198758624.003.0002
- Subject:
- Political Science, European Union
This chapter spells out the book’s research question and solves some definitional issues related to the dependent variable. The three main hypotheses which will structure the analysis throughout the ...
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This chapter spells out the book’s research question and solves some definitional issues related to the dependent variable. The three main hypotheses which will structure the analysis throughout the book are then presented. The theoretical framework adopted for the study is then specified. It is drawn from the Strategic Choice Approach (Lake and Powell, 1999). This framework allows for model assumptions and actor preferences to be specified. It also helps to deal with the thorny issue of the definition of a sub-state interest. The final section solves a series of methodological challenges. These are mostly related to endogeneity (regarding devolution and preference intensity levels) and to the effect of time as an omitted variable. The objective of the chapter is to clear the way for the analysis carried out in subsequent chapters.Less
This chapter spells out the book’s research question and solves some definitional issues related to the dependent variable. The three main hypotheses which will structure the analysis throughout the book are then presented. The theoretical framework adopted for the study is then specified. It is drawn from the Strategic Choice Approach (Lake and Powell, 1999). This framework allows for model assumptions and actor preferences to be specified. It also helps to deal with the thorny issue of the definition of a sub-state interest. The final section solves a series of methodological challenges. These are mostly related to endogeneity (regarding devolution and preference intensity levels) and to the effect of time as an omitted variable. The objective of the chapter is to clear the way for the analysis carried out in subsequent chapters.
